1. G. Porter, Opt. Spektrosk. 83(4), 534 (1997) [Opt. Spectrosc. 83 (4), 495 (1997)].
2. V. L. Ermolaev, E. N. Bodunov, E. N. Sveshnikova, and T. I. Shakhverdov, Nonradiative Transfer of Electronic Excitation Energy (Nauka, Leningrad, 1977) [in Russian].
3. S. A. Bagnich, Fiz. Tverd. Tela (St. Petersburg) 42(10), 1729 (2000) [Phys. Solid State 42 (10), 1775 (2000)].
4. M. I. Deryabin, O. I. Kulikova, and V. V. Solodunov, Zh. Prikl. Spektrosk. 67(6), 735 (2000).
5. A. B. Tishchenko, M. I. Deryabin, and O. I. Kulikova, Zh. Prikl. Spektrosk. 73(4), 550 (2006).